1. Field of the Invention
The present invention is in the field medical technologies and more particularly the treatment of tissue via a diffusion type device or dressings, the invention pertaining to charging and evacuation of such devices before use and during use.
2. Discussion of the State of the Art
In the medical field it is often required to treat tissue of patients in a manner which requires an extended period of bandaging or covering with medication diffusing patches or like devices that work to keep tissue moist, promote healing, to prevent maceration, possible infection, or to prevent any jolting or other physical disruption of a particular tissue area.
One example of such a therapeutic device is a multilayered diffusion dressing or device typically applied over a wound or graft to promote new skin growth in an area where the original skin was lost or removed by surgery. Such devices have different names in the art but may be technically referred to as therapeutic diffusion devices because of an active delivery (diffusion) of some therapeutic agent, often delivered in the form of a gas through an interfacing diffusion layer of the dressing or device to the affected tissue over time.
The inventor is aware of a diffusion device for treating tissue packaged according to a unique method the device including more than one device layer and at least one reservoir containing a therapeutic agent. The device is placed over top of a first packaging layer and a second packaging layer is placed over the top of the device. Seals are forged between the second packaging layer and the uppermost layer of the diffusion device and between the first packaging layer and an intermediate device layer. The packaging then may be removed by layer when the device is to be applied to tissue to be treated. Variances to the packaging method just described are also known to the inventor the variances including process variances and packaging material property variances that depend in part on device architecture and the therapeutic nature of the device.
A diffusion device for treating tissue is typically charged with some therapeutic agent that is expelled from the device through a diffusion process one effect there being that the dressing eventually becomes depleted of agent and is no longer therapeutic to the tissue being treated. Most such diffusion devices employ gasses infused into a reservoir in the device, the gases being diffused into a tissue area through a special diffusion layer of the device. Diffusion layers and adhesive layers for application of the dressing over a wound are typically a part of such apparatus.
It would be desirable to be able to charge a diffusion dressing with therapeutic agent both at pre-application and during active treatment of a patients wound or tissue area requiring treatment. Likewise, it would be desirable to be able to evacuate a therapeutic agent or in some cases exudates emanating from treated tissue from the diffusion device while it is being used.
Therefore, what are clearly needed are better methods and apparatus for charging and evacuating a diffusion device. Such methods would enable improved diagnostic and prognostic capabilities and would enable multiple therapies to be applied to a tissue area or wound without requiring removal and replacement of the diffusion device in use on the tissue or wound being treated.